Manipulating prefabricated flaps: An experimental study examining flap viability

As flap prefabrication becomes a more commonly used clinical tool, it is necessary to investigate the limitations of this technique. Reconstructive procedures of the face often require “custom fitted” flaps to satisfy esthetic demands. This study examines and compares the safety of manipulating thin prefabricated skin flaps versus established axial pattern skin flaps. Twenty-seven New Zealand white rabbits were used to determine if prefabricated flaps can be folded 180° around the edge of the rabbits' ears. The survival of these folded prefabricated flaps was compared with the survival of axial pattern flaps sutured into an identically recipient site. In addition, flaps prefabricated in the same manner were sutured onto a straight recipient bed to evaluate the viability of the newly vascularized tissue. The folded prefabricated flaps had reduced survival (56%) compared to equivalent folded axial pattern flaps (85%), P<0.005. The nonmanipulated prefabricated flaps and axial pattern flaps survived completely. © 1994 Wiley-Liss, Inc.     

Polymorphisms in tumor necrosis factor and other cytokines as risks for infectious diseases and the septic syndrome

An increasing number of genetic association studies have implicated polymorphisms of cytokine genes as host genetic factors influencing susceptibility to infectious disease, primarily using a candidate gene approach based on knowledge of disease pathogenesis. The application and limitations of association studies are reviewed together with the impact of recent advances in single nucleotide polymorphism mapping on strategic approaches to defining genetic susceptibility loci. It often remains unclear whether associated genetic polymorphisms are themselves functionally relevant or acting only as markers within an extended haplotype, and experimental approaches to investigating the functional impact of polymorphisms in noncoding regulatory DNA sequences are discussed. An overview of genetic associations of cytokine genes with infectious disease is presented, together with discussion of recent studies in a number of infectious diseases including hepatitis, HIV, malaria, and sepsis.     

Some features of Cannabis plants grown in the United Kingdom from seeds of known origin.

The cannabinoid content of UK-grown plants (up to the 6th generation) from Moroccan, Sri Lankan and Zambian seedstock was determined by TLC, GLC and HPLC. All plants from the 5th and 6th series resembled their parents, and UK-grown plants were always much greener than those grown overseas. Cannabinoid content remained broadly typical of the source countries. However, tetrahydrocannabinolic acid (THCA) consistently predominated over tetrahydrocannabinol (THC) to a far greater extent than in the original plants; the THCA/THC ratio was 17 in UK-grown plants compared with 2.0 in the plants from the original areas. Two types of plant emerged from the Moroccan seedstock, one tending to increased cannabidiol (CBD), the other tending to zero levels of this component. The first generation Sri Lankan plants revealed one type of plant with an increased CBD/THC ratio (1.7 compared with 0.11) but this returned to the original value in the succeeding generations. Other Sri Lankan plants had low or undetectable levels of CBD. Moroccan and Sri Lankan CBD-rich plants did not contain cannabichromene, although this cannabinoid was found in THC-rich plants. Zambian plants did not appear to show such a pattern. Zambian seedstock plants had total tetrahydrocannabivarin (diol and acid) levels greater than THC but the ratio was progressively reversed in succeeding generations. The study concludes that the ratios of particular cannabinoids is greatly influenced by the environment.     

The incidence of error in young children's Wh-questions.

Many current generativist theorists suggest that young children possess the grammatical principles of inversion required for question formation but make errors because they find it difficult to learn language-specific rules about how inversion applies. The present study analyzed longitudinal spontaneous sampled data from twelve 2-3-year-old English speaking children and the intensive diary data of 1 child (age 2;7 [years;months] to 2;11) in order to test some of these theories. The results indicated significantly different rates of error use across different auxiliaries. In particular, error rates differed across 2 forms of the same auxiliary subtype (e.g., auxiliary is vs. are), and auxiliary DO and modal auxiliaries attracted significantly higher rates of errors of inversion than other auxiliaries. The authors concluded that current generativist theories might have problems explaining the patterning of errors seen in children's questions, which might be more consistent with a constructivist account of development. However, constructivists need to devise more precise predictions in order to fully explain the acquisition of questions.